Evidence - The intraoral palpability of the lateral pterygoid muscle - A prospective study.

The intraoral palpability of the inferior caput of the lateral pterygoid muscle has been a matter of ambiguity because of its topography. Thus, none of the recently published studies has provided reliable proof of the possibility of digital intraoral palpation, although palpation of the muscle is part of most of the examination catalogs for clinical functional analysis and functional therapy. Digital muscle palpation was performed intraorally on five preparations after exposure of the infratemporal fossa and visualization of the lateral pterygoid muscle. Direct digital palpation of the lateral pterygoid muscle was seen in all five cases. The successful palpation was carried out and approved during laterotrusion to the examined side (relaxation). While opening and closing the mouth (contraction) the muscle is palpable. In real-time kinematic measurements (MRI) an impression of the lateral caput of the left lateral pterygoid muscle of a 30-year-old control male person was found up to 6mm. Electromyographic detection by direct signal conduction with concomitant palpation is possible. The injection electrode tested in situ in the muscle was felt transorally with the palpating finger. The intraoral palpability of the inferior caput of the lateral pterygoid muscle is verified. The basic requirement for successfully palpating the lateral pterygoid muscle is the exact knowledge of muscle topography and the intraoral palpation pathway. After documented palpation of the muscle belly in cadaverous preparations, MRI and EMG also visualized palpation of the lateral pterygoid muscle in vivo. The palpation technique seems to be essential and basically feasible.